MMSZ5245BT1G by Onsemi is a Zener diode with 15V nominal reference voltage, 8.5mA test current, and 16 ohm dynamic impedance. It is used in applications requiring precise voltage regulation in a compact SMD package for temperatures ranging from -55 to 150°C.
NE555DR by Texas Instruments is an Analog Waveform Generation IC with 8 terminals, operating voltage of 5V, and power supplies ranging from 5-15V. It is a versatile component for pulse generation applications due to its small outline package and commercial temperature grade suitability.